The present invention relates to a device, especially for cigarette-packaging machines, for joining the payed-out end of a strip, preferably a thin sheet of aluminum, paper, coated paper, plastic, or cellophane-like material, which had been wound into a reel, with the beginning of the strip of another reel. The device includes a buffer or storage device in which a certain length of the strip, which is conveyed over guide rollers, is stored and out of which that amount of strip necessary for continuous operation is withdrawn during the joining process. The device is also provided with a separating and binding device.
Devices for joining the tail end of a payed-out strand of material with the front end of a new strand are known, for example for cigarette-packaging machines. For example, German Pat. Nos. 1 141 848 and 1 250 229 show unwinding devices with which it is possible to switch a payed-out reel for a new strand reel without having to reduce the speed with which the strand is unwound. Due to the high output of the packaging machines, which must be supplied with strands or strips which are wound into reels, is necessary to frequently replace the reels. This replacement of the heavy reels is a burden on the operators, who have to be available for this purpose with each cycle. Threading the newly placed end of the thin sheet requires care and accuracy on the part of the operators if no breakdowns are to occur during the replacement of empty reels for available fill reels.
Numerous attempts have been made to carry out the replacement of the reels in a semi- or fully-automatic manner. Apart from the disturbances which occur during replacement of reels, the heretofore proposed constructions have the drawback that two reel-unwinding devices must be present for each strand; these devices not ony require a lot of space, but they also obstruct accessibility, especially with multi-strand or track machines.
It is an object of the present invention to avoid the drawbacks of the heretofore known devices for joining the payed-out end of a strand, which has been wound into a reel, with the beginning of the strip of a new reel, and to provide a device which, with little structural expense, makes it possible to rep1ace reels in a semi- or fully-automatic manner without encountering disturbances or interruptions.